Compositions of matter stabilized with isobornyl derivatives



Patented Feb. 17, 1953 UNITED ST TENT OFFICE COIVIPOSITIONS OF MATTERSTABILIZED WITH ISOBORNYL DERIVATIVES Thomas H. Newby, Middlebury, Conn,assignor to United States Rubber Company, New York, N. Y., a corporationof New Jersey No Drawing.

natural and synthetic, gasoline, transformer oils,

fats, Waxes, soaps, etc.

The aforesaid chemical may be prepared by reacting camphene withp-cresol in a 1:1 ratio, isolating the mono-isobornyl-p-cresol bydistillation, and reacting it with formaldehyde, in a 2:1 ratio. Theproduct thus obtained is 2. buffcolored solid which is an excellentantioxidant for rubber. How-ever, if the product of the initial reactionis not distilled but is reacted directly with formaldehyde, the productis a solid also possessing great antioxidant powers. Such a productconsists primarily of 6,6'-methylene bis- (2 isobornyl 4 methyl phenol)with lesser amounts of 2,6-'diisobornyl-4-methyl phenol and6,6'-methylene bis-(l-methyl phenol).

The two reactions involved in preparing the said compound of myinvention are as follows:

() OH OH CmHu + Cw le GE: CHI

Cm n

2 CHzO OH ()H CnoHu CH 010 11 I CH3 CH3 Any of the well-knownFriedel-Crafts catalysts may be used in step (a), and either an acidicor basic catalyst may be used in step (b). A preferred catalyst for bothreactions is boron fluoride etherate.

Aldehydes other than formaldehyde such as acetaldehyde, benzaldehyde,butyraldehyde, hept- Application November 30, 1950, Serial No. 198,500

4 Claims. (Cl. 260-45.95)

aldehyde, chloral, etc. also give products having antioxidantproperties; however, the formaldehyde derivative is preferred. Thealdehyde may be used in aqueous solution, in a polymeric form or as thepure aldehyde.

Examples of the other 6,6'--alkylidene bis-(2- isobornyl-4-methylphenols) include 6,6'-benzylidene bis-(2-isobornyl-4-methyl phenol),6,6- butylidene bis-(2-isobornyl-4-methyl phenol), 6,6-heptylidenebis-(2-isobornyl-4-methyl phenol), 6,6trichlorethylidenebis-(2-isobornyl-4- methyl phenol).

The following examples illustrate the invention:

EXAMPLE I One mole of p-cresol and 2 cc. of boron fluoride etherate areplaced in a reaction vessel and 1 mole of camphene is added slowly withstirring at C. The rate of addition of the camphene is used to controlthe reaction temperature between 90 C. and 119 C. After completeaddition of the camphene the mixture is heated for 3 hours at -110 C.Distillation of this product gives approximately a half-mole ofmono-isobornyl-p-cresol, B. P. 120-125" C./1 m-m.

One mole of isobornyl-p-cresol and 2 cc. of boron fluoride etherate aremixed and heated to 100 C. To this mixture is added one-half mole of 37%aqueous formaldehyde with stirring. After heating for 2 hours at 100 C.,the temperature is raised to C. for hour and then the product pouredonto a porcelain tray to cool. The crude product is ground and washedwith water to remove traces of formaldehyde. The washed product isrecrystallized from ligroin giving 6,6-methylenebis-(2-isobornyl-4-methyl phenol) having a constant melting range of120.5-l22 C.

Analysis Mol. Wgt. Percent C Percent H Calcd 500 84. 00 9. 60 Found 49283.59 10.62

EXAMPLE II The product prepared in Example I was incorporated int-o thefollowing stock for antioxidant Tetramethyl thiuram monosulfide 3 Theantioxidant was incorporated in the ratio of 1.0 part per 100 parts ofrubber. Cures were made for 10, 20,- and 30 minutes at 30 pounds steam.Table I shows percent tensile retained after aging 96 hours under 300pounds oxygen pressure at 70 C. and after 48 hours at 100 Cf in an airoven; also superiority-of the present chemical over 2-isoborny1-4-methylphenol. The

compound of my invention does not appreciably afiect the rubber cure,nor does it discolorthe-1o rubber nor stain lacquers nor fabric onexposure to sunlight.

TabZeI i j- Percent Percent 1 1; Tensile Tensile Antioxidant RetainedRetained The antioxidant may be used in crude form as prepared, or inmoreorless'pui-ifiedforms. H For purposes orretardin the deteriorationof the organic material; the amount of the chemical; may be variedaccording to the type and nature of the substance tobe. treated,beingusuany in small amounts ranging from 0.1 to 5 percent by. 30

'4 vulcanized or vulcanized rubber, as by surface application as bydipping the rubber or th like in a solution oremulsion of theantioxidant, or by adding it to the latex or other dispersion of therubber or the like, before, or during coagulation where such is desired.

,,The antioxidant can be used in any type or form of rubbercompositions, such as those used in the manufacture of tire carcasses,inner tubes, insulation, belting, hose, footwear, bath caps, hot waterbottles,-dipped goods, and the like.

The" components of the composition containing the antioxidant may beused in various ratios,

and it is not intended to limit the invention to 5 the amou ots ofingredients indicated in the example given.

Having thus described my invention, what I claim' a'rid' desire to'protect'by Letters Patent is:

1. An organic substance which tends to deterio'rate by absorption ofoxygen from the air containing in antioxidant amount, a 6,6"- a1ky1i-"dene bis (2 iso'bornyl-4-methyl phenol) 2. Anbrganic substance whichtends to deteriorate by absorption of oxygen from the air 5 containingin antioxidant amount, '6,6-methy1- ene' bis- (2-isoborny1-4-methylphenol) 3. A rubber composition containing in anti oxidant amount, a6,6i-alkylidene bis-(2-isobornyl--methyl phenol). a

.4. A. rubbercomposition;containing, in. antioxidant amount,6,6-methy1-ene bis-(2-isobornyia-methyl pheno1'). iTI-IOMAS.H.:NEWBY.

REFERENCES CITED f .7

The following references are of record in the file of this patent: V Y IUNITED STATESPATEN'IS 7 Date 0 Number Name 1,989,788 Calcott et a1."Feb. 5, 1935 2,471,453 'Rummelsburg May 31, 1949 2,537,636 Kitchen Jan.9, 1951

1. AN ORGANIC SUBSTANCE WHICH TENDS TO DETERIORATE BY ABSORPTION OFOXYGEN FROM THE AIR CONTAINING IN ANTIOXIDANT AMOUNT, A 6,6''-ALKYLIDENEBIS-(2-ISOBORNYL-4-METHYL PHENOL).